/Engine/Source/Runtime/Engine/Classes/GameFramework/CharacterMovementComponent.h
Custom version of SlideAlongSurface that handles different movement modes separately; namely during walking physics we might not want to slide up slopes.
virtual float SlideAlongSurface ( const FVector & Delta, float Time, const FVector & Normal, [FHitResult](API\Runtime\Engine\Engine\FHitResult) & Hit, bool bHandleImpact )